Error in mosaic

Hello. I want to mosaic the four images of the Sentinel 2. But I get this error:

I do not understand the meaning of the error. I will be grateful if you can guide me

If I see it correctly, you have specified a pixel size of 100°.
For your input data the results in a target scene with less 1 pixel.

I have tried with different numers. What number should i enter?

This error occurs when numbers above one are entered. It can be used for numbers below one, but no image is created

One s2 granule covers an area of roughly 100x100 km. So less than one degree.
So, try something like 0.001. In the end it depends on your needs what you enter. Maybe you want to specify 0.0001 or just 0.01.

Thank you very much. I was able to do it with the number 0.001. I was involved in it for a few days. You helped a lot.